There exists a need in motion control applications for the use of stepper motors as through-hole motors in semiconductor, manufacturing and medical processes that use light emitted by lasers, radar positioning pedestals, and environmentally controlled chambers. Current step motor designs do not easily adapt to such through motor applications without substantial modification.
One example of a stepper motor having an internal opening is found in U.S. Pat. No. 6,002,186 entitled Electrical Stepper Motor Having a Cylindrical Magnetic Rotor within a Pair of Cups of Magnetic Material”.
The advent of such a stepper motor having an internal opening for semiconductor, manufacturing and medical applications, has occasioned demand for such motors having higher power applications, not achievable by the power rating of the aforementioned U.S. Pat. No. 6,002,186.
One purpose of the invention is to describe a stepper motor having an internal opening through the center of the motor with increased motor torque efficiency. The motor includes means for providing increased power capacity without interfering with the internal opening advantages.